Terminal unit, position display method, information providing system, and information providing method

ABSTRACT

A radiocommunication system including a portable terminal, a base station and a server. The portable terminal transmits a destination to the server and further sends the ID number (CS — ID) of the base station coupled through a radio link to the portable terminal. The server has a table representative of a corresponding relationship between the ID number of the base station and the standing position of the base station and retrieves the position corresponding to the ID number thereof as the present position of the portable terminal from the table. Further, the server transmits map data corresponding to the present position of the portable terminal to the portable terminal.

This is a continuation of application Ser. No. 09/859,030, filed May 16,2001 now U.S. Pat. No. 6,907,255, which is a continuation of applicationSer. No. 08/771,146, filed Dec. 20, 1996, now U.S. Pat. No. 6,314,295,the entirety of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a terminal unit, a position displaymethod, an information providing system and an information providingmethod which are suitably applicable to an navigation system.

2. Description of the Related Art

FIG. 17 shows an example of an arrangement of an navigation system usinga prior portable terminal. A plurality of low orbiting satellites 10Aand 10B (although two in the illustration, in general at least three loworbiting satellites) constitute a GPS (Global Positioning System) andorbit around the earth at a relatively low position. A portable terminal11 receives radio waves emitted from the low orbiting satellites 10A,10B to calculate its own present position.

FIG. 18 is an illustration of an example of an arrangement of theportable terminal 11. In FIG. 18, a CPU 31 executes various processes inaccordance with programs stored in a ROM 32, and a RAM 33 stores data,programs and others necessary for the various processes the CPUimplements. An input section 40 is used when the user of the portableterminal 11 inputs given instructions, and a display section 38 iscomposed of a liquid crystal display device or the like to displaypictures such as given letters and graphic patterns. A receiving circuit36 receives, through an antenna 35, radio waves outputted from the loworbiting satellites 10A, 10B to output a demodulated signal to anarithmetic circuit 37. The arithmetic circuit 37 operates the signal fedfrom the receiving circuit 36 to obtain the present position (latitudeand longitude) and outputs it to the CPU 31. A reproducing unit 39reproduces map data recorded in a recording medium such as a CD-ROM andmakes the display section 38 display it. An interface 34 performs theinterface processing for the arithmetic circuit 37, the display section38, the reproducing unit 39 and the input section 40.

In this example, the display section 38 displays the map data thereproducing circuit 39 reproduces from the CD-ROM, and when taking inthe position information expressed with the latitude and the longitudefrom the arithmetic circuit 37, the CPU 31 produces a picture of apresent position indicating mark corresponding to that position andoutputs the picture via the interface 34 to the display section 38 whichin turn, displays the picture. Thus, the map and the present positionappear on the display section 38.

FIG. 19 shows another example of an arrangement of a navigation system.A portable terminal 20 transmits and receives radio waves to and fromthe nearest base stations 21A, 21B and gains access through a network 23with an exchange 22 to, for example, a given database 24. FIG. 20 is anillustration of an example of an arrangement of the portable terminal20. In FIG. 20, a CPU 61 executes various processes in accordance withprograms stored in a ROM 62 and suitably makes a RAM 63 store data orthe like. An input section 67 is operated for when the user of theportable terminal 20 inputs given instructions. A reproducing unit 66reproduces map data recorded in a CD-ROM or the like so that the mapdata is displayed on a display section 65. A communication circuit 69establishes communications with the neighboring base station of the basestations including the base stations 21A, 21B. An interface 64 carriesout the interface processing for the reproducing unit 66, the displaysection 65, the input section 67 and the communication circuit 69.

In this example, as well as the FIG. 18 portable terminal 11, thereproducing unit 66 reproduces a map from the CD-ROM and the displaysection 65 displays it, whereas a method of detecting the presentposition differs from that in the FIG. 18 terminal 11. That is, in thisexample, when establishing communication via the communication circuit69 to the adjacent base station (for example, the base station 21A), theCPU 61 gets an ID (IDentification) number of the base station 21A. Sincethe base stations 21A, 21B are all equipment fixed at given locations,the positions thereof are known in advance. Accordingly, the position ofthe base station which is in connecting relation to the portableterminal 20 can be specified by the ID number thereof. For instance, ifthe RAM 63 stores a corresponding table between the ID numbers of therespective base stations and the positions of the base stations, whenreceiving the ID number of a base station, the CPU 61 can find theposition corresponding to the ID number referring to the table the RAM63 retains therein. In addition, the CPU 61 can make the display section65 display the obtained position as the present position.

There is a problem which arises with any one of the conventionalportable terminals, however, in that the system increases in size andcost because the reproducing unit 39 or 60 is designed to reproduce themap data. Further, in the case of the FIG. 20 portable terminal 20,since the RAM 63 needs to store the table representative of thecorresponding relationship between the ID numbers of the respective basestations and the positions thereof, the increase in the capacity of theRAM 63 is necessary not only to increase the dimension of the portableterminal 20 but also to raise the cost thereof. Still further, in thecase of the FIG. 18 portable terminal 11, since the arithmetic circuit37 is made to calculate the latitude and longitude of the presentposition, the circuit scale of the arithmetic circuit 37 increases insize and in cost.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide aportable terminal which is smaller in size, low in cost and convenientto carry.

For the elimination of the above-mentioned problems, a terminal unitaccording to the present invention comprises detection means fordetecting a signal to be used for the determination of the presentposition, transmission means for transmitting the signal detected by thedetection means to an external processing unit which determines thepresent position, reception means for receiving position information onthe present position the external processing unit determines, and outputmeans for combining the position information the reception meansreceives with map information and for outputting the combination result.

In addition, a position display method according to this inventioncomprises a detection step of detecting a signal for determining thepresent position, a transmission step of transmitting the signaldetected through the detection step to an external processing unit whichdetermines the present position, a reception step of receiving positioninformation on the present position determined in the externalprocessing unit, and an output step of combining the positioninformation the reception step receives with map information to outputthe combination result.

Furthermore, another terminal unit according to this invention isequipped with position detection means for detecting the presentposition, transmission means for transmitting the present position theposition detection means detects to an external processing unit,reception means for receiving map information including the presentposition from the external processing unit, and output means forcombining the map information the reception means receives with theposition information the position detection means detects and foroutputting the combination result.

Furthermore, another position display method according to this inventioncomprises a position detection step of detecting the present position, atransmission step of transmitting the present position detected throughthe position detection step to an external processing unit, a receptionstep of receiving map information including the present position fromthe external processing unit, and an output step of combining the mapinformation received through the reception step with the positioninformation detected through the position detection step and foroutputting the combination result.

Furthermore, a different terminal unit according to this invention isprovided with input means for performing the input of destinationinformation, transmission means for transmitting the destinationinformation inputted through the input means to an external processingunit which calculates position information on the destination, receptionmeans for receiving the position information on the destinationcalculated in the external processing unit, and output means forcombining the position information from the reception means with mapinformation and for outputting the combination result.

Furthermore, a different position display method according to thisinvention comprises an input step for performing the input ofdestination information, a transmission step of transmitting thedestination information inputted through the input step to an externalprocessing unit which calculates position information on thedestination, a reception step of receiving the position information onthe destination calculated in the external processing unit, and anoutput step of combining the position information received through thereception step with map information to output the combination result.

Furthermore, a different terminal unit according to this invention iscomposed of detection means for detecting a signal for determining thepresent position, input means for performing the input of destinationinformation, transmission means for transmitting the present positiondetermining signal detected by the detection means and the destinationinformation inputted through the input means to an external processingunit which determines present position information and destinationposition information, reception means for receiving the present positioninformation and the destination position information determined in theexternal processing unit, and output means for combining the presentposition information and destination position information the receptionmeans receives with map information and for outputting the combinationresult.

Furthermore, a different position display method according to thisinvention comprises a detection step of detecting a signal fordetermining the present position, an input step of performing the inputof destination information, a transmission step of transmitting thepresent position determining signal detected through the detection stepand the destination information inputted through the input step to anexternal processing unit which determines present position informationand destination position information, a reception step of receiving thepresent position information and destination position informationdetermined in the external processing unit, and an output step ofcombining the present position information and destination positioninformation obtained through the reception step with map information tooutput the combination result.

Still further, an information providing system comprises reception meansfor receiving a signal indicative of the present position of a terminalunit connected through a communication line thereto, determination meansfor determining the present position of the terminal unit on the basisof the signal the reception means receives, and transmission means fortransmitting the present position determined by the determination meansto the terminal unit.

Moreover, an information providing method according to this inventioncomprises a reception step of receiving a signal indicative of thepresent position of a terminal unit connected via a communication linethereto, a determination step of determining the present position of theterminal unit on the basis of the signal obtained through the receptionstep, and a transmission step of transmitting the present positiondetermined through the determination step to the terminal unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The object and features of the present invention will become morereadily apparent from the following detailed description of thepreferred embodiments taken in conjunction with the accompanyingdrawings in which:

FIG. 1 is an illustration of an arrangement of a simplified typeportable telephone system adopting a terminal unit according to thepresent invention;

FIG. 2 is a block diagram showing an example of an arrangement of aportable terminal (81) in FIG. 1;

FIG. 3 is a block diagram showing an example of an arrangement of aserver (86) in FIG. 1;

FIG. 4 is a flow chart useful for describing an operation of the FIG. 1embodiment;

FIG. 5 is an illustration available for explaining the cover areas ofbase stations;

FIG. 6 shows an example of a table representing a correspondingrelationship between an ID number of a base station and a positionthereof;

FIG. 7 is an illustration of a display example on a display section (95)in FIG. 2;

FIG. 8 is an illustration of another display example on a displaysection (95) in FIG. 2;

FIG. 9 is a flow chart for describing a line monitoring processingoperation of a server (86) in FIG. 3;

FIG. 10 is a block diagram showing another arrangement example of aportable terminal (81) according to this invention;

FIG. 11 is an illustration of an example of a display on a displaysection (95) in FIG. 10;

FIG. 12 is a block diagram showing a different arrangement example of aportable terminal (81) according to this invention;

FIG. 13 is a flow chart useful for explaining an operation of a portableterminal (81) in FIG. 12;

FIG. 14 is a block diagram showing a different arrangement example of aportable terminal (81) according to this invention;

FIG. 15 is a flow chart for describing an operation of a portableterminal in FIG. 14;

FIG. 16 is a block diagram showing a different example of an arrangementof a portable terminal (81) according to this invention;

FIG. 17 is an illustration for describing a Global Positioning System;

FIG. 18 is a block diagram showing an arrangement example of a portableterminal (11) in FIG. 17;

FIG. 19 is an illustration of an arrangement of a radiocommunicationsystem network; and

FIG. 20 is a block diagram showing an arrangement example of a portableterminal (20) in FIG. 19.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is an illustration of an arrangement of a navigation systemadopting a terminal unit according to the present invention. In FIG. 1,a portable terminal 81 is a portable terminal subscribing for a portabletelephone system, and a portable telephone system network 82 of anenterpriser for which the portable terminal 81 subscribes includes apublic network 83 with an exchange 84 and a plurality of base stations85A, 85B (of the plurality of base stations, two illustrated in FIG. 1).The portable terminal 81 is made to be capable of establishingcommunications through radio waves with the nearest base station of theplurality of base stations 85 (if not necessary to distinguish amongthem, all the base stations including the base stations 85A, 85B arewholly referred to as base stations 85). In this embodiment, for thedescription only, a PHS (Personal Handy Phone System) is used as oneexample of the portable telephone system network. The PHS is one of themobile station communication systems in Japan where radio base stationsare installed at an interval of several hundred meters in the outdoorplaces and telephone terminal units periodically transmit and receiveposition information to and from the neighboring base station of aplurality of base stations and make communications through this basestation with different telephone terminal units. Further, when adoptingthe TDD (Time Division Duplex) method, the PHS compresses the auralsignal in a state with dividing it with time to accomplish thetransmission and reception at one carrier frequency. Moreover, whenemploying the TDMA (Time Division Multiple Access) method, the PHSperforms the multiplex communications in such a manner as to divide fourchannels with time at one carrier frequency. The frequency band used forthe communications by the PHS is 1.9 GHz, and the digital datacommunication is possible at a transmission speed of 32 kbit/sec per onechannel. If one terminal uses a plurality of channels, the datatransmission is possible at a maximum of 128 kbit/sec (32 k×4 channels).

In addition, The public network 83 is in connecting relation to a server86 which in turn, is in connecting relation to a database 87.

The portable terminal 81 has an arrangement, for example, as shown inFIG. 2. In FIG. 2, a CPU 91 executes various processes in accordancewith programs stored in a ROM 92, and a RAM 93 is designed to storeprograms and data necessary for the various processes in the CPU. Aninput section 96 is composed of buttons, switches, keys and others, withthe user of the portable terminal 81 operating the input section 96 toinput given instructions via an interface 94 to the CPU 91. In addition,if given input takes place through voices, the input section 96 furtherincludes a microphone for receiving the voices. The input section 96 isadditionally equipped with an IC card reading unit for reading from anIC card.

A display section 95 is constructed with a liquid crystal display deviceand displays pictures such as letters and graphic patterns fed via theinterface 94, and a communication circuit 98 establishes radio wavecommunications through an antenna 97 with a given base station 85.

On the other hand, a server 86 has an arrangement, for example, as shownin FIG. 3. A CPU 111 executes various processes in accordance withprograms stored in a ROM 112, and a RAM 113 suitably stores programs anddata necessary for the various processes in the CPU 111. An inputsection 117 is composed of a keyboard, a mouse, a microphone and othersand is operated when inputting various instructions. A speechrecognition section 115 recognizes an aural signal inputted through acommunication circuit 114 and outputs the recognition result through aninterface 118 to the CPU 111. Further, a display section 116 isconstructed with a liquid crystal display device, a CRT or the like anddisplays pictures such as characters and graphic patterns inputted viathe interface 118. The aforesaid communication circuit 114 is designedto make communications through the portable telephone system network 82and the public network 83 with the portable terminal 81.

Secondly, an operation thereof will be described hereinbelow referringto a flow chart of FIG. 4. First of all, at step S1 the user operatesthe input section 96 of the portable terminal 81 to make connection of aline through the portable telephone system network 82 to the server 86.In addition, at this time, the CPU 91 gets, as the present position, theID number (CS_(—)ID) (an identification number for identifying each ofbase stations) of the base station 85 establishing a communication linktherewith and makes the RAM 93 store it. In addition, the CPU 91 makes anavigation service request to the server 86. Subsequently, at step S2the CPU 91 outputs the destination information and the ID number of thebase station 85 connected to the communication line through thecommunication circuit 98 to the server 86.

In the PHS, as shown in FIG. 5 the base station 85 is installed withineach of cover areas having a radius of approximately 100 meters. For thecommunication, each of the base stations 85 gives and receives a radiowave to and from the portable terminal 81 standing within thecorresponding cover area. Accordingly, when the portable terminal 81sets up a communication link with a given base station 85 (for example,the base station 85A in FIG. 1), an estimation can be made such that theportable terminal 81 exists within the cover area of that base station85 (in the above example, the base station 85A).

Thus, if as shown in FIG. 6 the corresponding relationship between theID number of each of the base stations 85 and the cover area (position)thereof is stored in the form of a table in the RAM 113 of the server 86in advance, when receiving the ID number of the base station from theportable terminal 81, the server 86 can detect that cover area (thepresent position of the portable terminal 81) on the basis of the IDnumber. For example, in the case of the FIG. 6 example, if the ID numberof the base station 85 is 0002, an decision can be made to that theportable terminal 81 stands within a range of the north latitude 35degrees 55 minutes 25 seconds to 35 degrees 56 minutes 10 seconds andthe east longitude 135 degrees 15 minutes 25 seconds to 135 degrees 16minutes 5 seconds. Accordingly, the CPU 91 of the portable terminal 81transmits the ID number of the base station 85 as the present positionat the step S2.

Furthermore, for example, the destination of the movement of the usercarrying the portable terminal 81 can be inputted as follows. The firstinput method relates to inputting the telephone number of thedestination through the operation of the keys of the input section 96.In response to the input of the destination telephone number from theinput section 96, the CPU 91 outputs the telephone number via thecommunication circuit 98 to the server 86. When the server 86 receivesthis telephone number through the communication circuit 114, the CPU 111sets up access through the communication circuit 114 to the database 87to retrieve the address corresponding to the telephone number andfurther to retrieve the position (latitude and longitude) of theaddress. Further, the CPU 111 makes the RAM 113 store the obtainedposition information as the position of the destination of the portableterminal 81.

The second input method relates to a method in which the user inputs thedestination with a speech through a microphone of the input section 96.The CPU 91 outputs the aural signal through the communication circuit 98to the server 86. When the server 86 receives the aural signal throughthe communication circuit 114, the speech recognition section 115performs the speech recognition processing. The CPU 111 retrieves theposition information (for example, latitude and longitude) correspondingto the place name attained through the speech recognition from thedatabase 87. The position information is stored as the position of thedestination of the portable terminal 81 in the RAM 113.

As the third input method, a method is available to use an IC card. Inthis instance, an IC card reading unit provided in the input section 96is used. In this IC card, the position data (latitude and longitude) ofthe destination are registered in advance through the use of a personalcomputer or the like. When this IC card is mounted in the card readingunit provided in the input section 96, the CPU 91 reads out the datatherefrom and sends it through the communication circuit 98 to theserver 86. Incidentally, it is also appropriate that a plurality of dataare stored in advance in the IC card through a personal computer. Thatis, when the IC card is mounted in the IC card reading unit of the inputsection 96, the CPU 91 reads out the plurality of previously storedposition data from the IC card and displays these position data on thedisplay section 95 in the form of a list. The user using the portableterminal 81 uses keys on the input section 96 to select the positiondata to be set as the destination from the plurality of position datadisplayed on the display section 95. The CPU 91 transmits the positiondata, selected by the user, through the communication circuit 98 to theserver 86.

The fourth input method relates to a method in which the user directlyinputs the latitude and longitude of the destination as numeric data. Inthis case, the user inputs the latitude and longitude values of thedestination through the use of the keys fitted on the input section 96of the portable terminal 81. The CPU 91 makes the RAM 93 temporarilystore the numeric data on the latitude and longitude inputted by theuser and then transmits them via the communication circuit 98 to theserver 86.

The fifth input method is a method to input the destination on the basisof map data displayed on the display section 95. The CPU 91 of theterminal unit 81 issues a map data request command to the server 86. Inresponse to the reception of the map data request command, the CPU 111of the server 86 extracts the map data from the database 87 and sendsthe map data via the communication circuit 114 to the terminal unit 81.The terminal unit 81, receiving the map data via the communicationcircuit 98, accumulates the map data in the RAM 93 and displays it onthe display section 95. The user, using the terminal unit 81, indicatesthe area of the vicinity of the destination through the input section 96on the basis of the map data displayed on the display section 95. TheCPU 91 retrieves the position information on the area of the vicinity ofthe destination inputted through the input section 96 from the map datastored in the RAM 93 and transmits the position information via throughthe communication circuit 98 to the server 86. In response to thereception of the position information, the server 86 selects moredetailed map data (that is, the map data different in scale) from thedatabase 87 and sends it via the communication circuit 114 to theterminal unit 81. When receiving new map data, the terminal unit 81makes the RAM 93 store the new map data and display section 95 displayit. When the user sets the destination on a map through the inputsection 96 on the basis of the new map data (the detailed map data)displayed on the display section 95, the CPU 91 retrieves the positioninformation (latitude and longitude) on the destination from the mapdata stored in the RAM 93 and transmits the retrieval result as thedestination position information via the communication circuit 98 to theserver 86.

In response to the above-mentioned supply of the present position (thecover area of the base station 85) and the destination positioninformation, at step S3 the CPU 111 of the server 86 reads out the mapdata including the present position and the destination from thedatabase 87 and transmits it to the portable terminal 81. In response tothe input of the map data via the communication circuit 98, the CPU 91of the portable terminal 81 once stores that data in the RAM 93 andreads out that data for displaying on the display section 95. Whereupon,for example, as shown in FIG. 7 a map on which the present position markand the destination mark are superimposed is displayed on the displaysection 95.

Thus, in this embodiment the present position, the destination positioninformation and the map data are supplied from the server 86 to theportable terminal 81. In addition, the CPU 91 of the portable terminal81 reads out the present position mark (a circle mark in FIG. 7) and thedestination mark (x mark in FIG. 7) stored in the RAM 93 andsuperimposes or places the marks on the map data on the basis of theposition information sent from the server 86 to display them on thedisplay section 95 as shown in FIG. 7. Accordingly, it is possible tomore simplify the arrangement of the portable terminal 81 in the mannerthat the present position and the destination position are also placedunder the control of the server 86. Incidentally, it is also appropriatethat the present position mark and the destination mark to be displayedon the display section 95 are designed to be fed from the server 86.

Furthermore, in cases where the destination and the present position aregreatly remote from each other so that a map including both thedestination and present position is difficult to display on the displaysection 95 of the portable terminal 81, the CPU 111 of the server 86calculates the direction of the destination viewed from the presentposition on the basis of the position information on the presentposition and the destination. Thereafter, the server 86 transmits theposition information on the portable terminal 81, the directioninformation on the destination, together with the map data, to theportable terminal 81. On the basis of the received position informationand destination direction information, the CPU 91 of the portableterminal 81 displays, on the display section 95, the superimposition ofthe present position and an arrow indicative of the direction of thedestination viewed from the present position on a map as shown in FIG.8.

When the user carrying the portable terminal 81 moves to shift from thecover area of the base station 85 till now to the cover area of adifferent base station 85, in the case of the PHS, an handoverprocessing is conducted to again establish a radio link with the newbase station 85. When this handover processing is conducted, at step S4the CPU 91 of the portable terminal 81 gets the ID number of the newbase station 85 and then transmits it to the server 86. In response tothe reception of the ID number of the new base station 85, at step S5the CPU 111 of the server 86 newly outputs the present position(latitude and longitude) of the portable terminal 81 via thecommunication circuit 114 to the portable terminal 81. On receiving thenew present position, the CPU 91 of the portable terminal 81 makes theRAM 93 stores the new present position and then reads it out to updatethe display on the display section 95. Whereupon, the display of thepresent position is renewed whenever the portable terminal 81 shifts toa new cover area. If the range of the map stored in the RAM 93 anddisplayed on the display section 95 comes to a difficulty of coveringthe present position or the destination, the CPU 91 of the portableterminal 81 makes a request for the transfer of new map data toward theserver 86. In this way, the user can reach the destination referring tothe map displayed on the display section 95.

For terminating the reception of the navigation service, the useroperates the input section 96 to give instructions for termination tothe CPU 91. At this time, at step S6 the CPU 91 outputs a servicetermination request signal to the server 86, and at step S7 the CPU 91controls the communication circuit 98 to implement the line cut-offprocessing. It is also possible to carry out this cut-off processing inthe server 86 side.

In the case of the PHS, when extending over an exchange and moving tothe cover area of a base station connected to a different exchange, thehandover comes to difficulty. For this reason, the moment that thehandover extending over the exchange takes place, the line is cut. Inconsequence, it is impossible that the portable terminal 81 continuouslyreceives the navigation service from the server 86. Thus, the CPU 111 ofthe server 86 performs a line monitoring process as shown in FIG. 9while supplying the navigation service. That is, first of all, at stepS11 the CPU 111 decides, through the handover extending over theexchange, whether the line is cut off or not. If not cut, a givenprocess is conducted till disconnection. Further, if the answer of stepS11 indicates that the line is cut off, the operational flow goes to astep S12 to check whether or not the portable terminal 81 is nowreceiving the navigation service. If not receiving the navigationservice, the operational flow returns to the step S11 to repeatedlyexecute the following processes. On the other hand, if the decision ofthe step S12 is the reception of the navigation service, the operationalflow advances to a step S13 where the CPU 111 again conducts the lineconnecting process to the portable terminal 81.

In this way, in cases where the line comes into disconnection because ofthe handover extending over the exchange, the server 86 automaticallyperforms the line connecting process to the portable terminal 81 tocontinuously supply the navigation service. It is also possible thatthis line monitoring process is conducted in the CPU 91 of the portableterminal 81. Thus, even if the line is temporarily disconnected due tothe handover extending over the exchange, when the line connectingprocess is quickly done in such a way, the map data stored in the RAM 93continuously appears on the display section 95, and therefore the usercan substantially receive the navigation service from the server 86without noticing the fact of the disconnection of the line.

The FIG. 2 embodiment can not detect the direction of movement of theportable terminal 81. Thus, for example, as shown in FIG. 10 an azimuthmagnet 131 is provided in the portable terminal 81 to sense thedirection in which the portable terminal 81 moves. On the basis ofdirection information obtained from the azimuth magnet 131, as shown inFIG. 11 the CPU 91 of the portable terminal 81 displays, on the displaysection 95, the data produced by together superimposing a circle markindicative of the present position and an arrow mark representative ofthe direction of movement of the portable terminal 81 on a map. In thisway, the user can find the direction of the portable terminal 81 on themap.

It is also appropriate that the portable terminal 81 transfers theadvancing direction detected by the azimuth magnet 131 to the server 86.In this case, the CPU 111 of the server 86 superimposes an arrow markindicative of the advancing direction of the portable terminal 81 on amap and then sends the map data to the portable terminal 81. Further, itis also possible that the previous position information on the coverareas is stored in the RAM 93 so that the CPU 91 of the portableterminal 81 calculates the difference between the present cover areaposition information and the previous cover area position information tomake the display section 95 display the advancing direction of theportable terminal 81 on the basis of the difference information. Stillfurther, it is also possible that the previous cover area positioninformation is stored in the RAM 113 of the server 86 so that the CPU111 of the server 86 obtains the difference between the present coverarea position information on the portable terminal 81 and the previouscover area position information thereon to calculate the movingdirection of the portable terminal 81 on the basis of the differenceinformation and to transmit the advancing direction to the portableterminal 81.

Although in this embodiment the CPU 91 of the portable terminal 81places, on the map data, the marks indicative of the present position,the destination, the direction of the destination and the movingdirection to be displayed on the display section 95, it is also possiblethat the CPU 111 of the server 86 accomplishes the superimposition ofthese marks on the map information and then transmits the mapinformation to the portable terminal 81. With this arrangement, theprocessing load in the portable terminal 81 is reducible and thereduction of the portable terminal 81 in size is possible. Further,although the PHS is used as an example of the portable telephone system,it is also possible to employ a different radio telephone system (forexample, a digital cellular system).

Although in the above-described embodiments the present position isdetected on the basis of the cover area of the base station 85, it ispossible to detect the present position on the basis of the radio wavefrom the GPS. That is, in this case, as shown in FIG. 12 the portableterminal 81 is provided with a receiving circuit 142 having a GPSantenna 141. The receiving circuit 142 receives, through the GPS antenna141, the radio wave emitted from low orbiting satellites and demodulatesit. A GPS arithmetic circuit 143 calculates the present position(latitude and longitude) on the basis of the demodulation output. TheCPU 91 transfers this present position via the communication circuit 98to the server 86. When receiving this present position through thecommunication circuit 114, the CPU 111 of the server 86 retrieves themap data corresponding to the present position from the database 87 andtransmits it via the communication circuit 114 to the portable terminal81.

In the case of constructing the portable terminal 81 as shown in FIG.12, the operation is conducted as shown in FIG. 13. That is, first ofall, at step S21 the CPU 91 of the portable terminal 81 performs theline connecting processing to the server 86. Further, on the connectionof the line, at step S22 the CPU 91 sends the present position dataobtained through the calculation in the GPS arithmetic circuit 143 viathe communication circuit 98 to the server 86. In addition, at thistime, the CPU 91 also transmits the destination inputted through theinput section 96 in accordance with the above-mentioned method to theserver 86. When receiving the data comprising the destination and thepresent position from the portable terminal 81 through the communicationcircuit 114, the CPU 111 of the server 86 retrieves the map dataincluding the destination and the present position from the database 87.Further, at step S23 the CPU 111 transmits the map data via thecommunication circuit 114 to the portable terminal 81.

The CPU 91 of the portable terminal 81 receives this map data throughthe communication circuit 98 and makes the RAM 93 once store this mapdata and then reads out the map data to display it on the displaysection 95. Accordingly, the user can move for the destination referringto the map on the display section 95. Further, on the reception of themap data from the server 86, the CPU 91 starts a built-in timer. Oncounting a given time, at step S24 the CPU 91 reads out the presentposition calculated in the GPS arithmetic circuit 143 at that time andagain sends the calculation result (present position) to the server 86.On receiving the new present position data, the CPU 111 of the server 86obtains the location of the present position on the map. Subsequently,at step S25 the CPU 111 again transmits the obtained positioninformation on the map to the portable terminal 81.

With the repetition of the above-mentioned operation, whenever a giventime period passes, a map on which a new present position issuperimposed is displayed on the display section 95 of the portableterminal 81. If the range of the map stored in the RAM 93 comes todifficulty of covering the present position or the destination, as wellas the above-mentioned case, new map data is transferred from the server86. The operations in steps S26 and S27 for the termination of thenavigation service are the same as those in the steps S6 and S7 of FIG.4.

The receiving circuit 142 and the GPS arithmetic circuit 143 in FIG. 12substantially have the same arrangements as those of the receivingcircuit 36 and the arithmetic circuit 37 in FIG. 18. However, unlike theFIG. 18 example, in the FIG. 12 embodiment the map data is notreproduced through the reproducing unit 39 but is obtained from theserver 86, with the result that the arrangement of the portable terminal81 can be simplified by a quantity corresponding to the arrangement ofthe reproducing unit 39, thus suppressing the increase in dimension.

The omission of the GPS arithmetic circuit 143 is also possible. In thisinstance, the CPU 91 of the portable terminal 81 implements the lineconnecting processing to the server 86. The CPU 91 of the portableterminal 81 sends the demodulated signal demodulated by the receivingcircuit 142, together with the destination data, via the communicationcircuit 97 to the server 86. On receiving the demodulated signal, theserver 86 calculates the present position (latitude and longitude) ofthe portable terminal 81 on the basis of the demodulated signal from theportable terminal 81. On the basis of this present position, the CPU 111of the server 86 retrieves, from the database 87, the map data includingthe destination from the portable terminal 81 and the calculated presentposition of the portable terminal 81. Further, the CPU 111 sends the mapdata via the communication circuit 114 to the portable terminal 81. Thefollowing operations (the step S23 and the following steps in FIG. 13)are the same as those in the above-described embodiment. With thisarrangement, the necessity to include the GPS arithmetic circuit 143 inthe portable terminal 81 side is eliminable, thus further reducing thesize of the portable terminal 81.

FIG. 14 shows a different arrangement of the portable terminal 81. Inaddition to the embodiment as shown in FIG. 10, this embodiment includesa VICS (Vehicle Information and Communication System) arithmetic circuit152 equipped with a VICS antenna 151. The VICS is a system for supplyingthe traffic information through beacons installed on given positions ofa road to motor vehicles or the like, and further transmits the positioninformation on each of the beacons, and hence the position informationon the beacons is obtainable in a manner that the VICS arithmeticcircuit 152 demodulates the radio wave captured through the VICS antenna151. Thus, the CPU 91 can detect as the present position of the portableterminal 81 the position information obtained by the VICS arithmeticcircuit 152.

In the case of constructing the portable terminal 81 as shown in FIG.14, the operation between the portable terminal 81 and the server 86 ismade as shown in the flow chart of FIG. 15. That is, at step S31 the CPU91 of the portable terminal 81 performs the line connecting processingto the server 86, and when the line comes into connection, at step S32the CPU 91 transmits the present position (VICS operation result)obtained by the VICS arithmetic circuit 152 and the destination data tothe server 86. At step S33 the server 86 retrieves the map datacorresponding to the destination and the present position from thedatabase 87 and sends it to the portable terminal 81. When the VICSarithmetic circuit 152 gets new position information, at step S34 theCPU 91 sends the VICS operation result to the server 86. Further, atstep S35 the server 86 accordingly transmits the position information ona map corresponding to the new present position to the portable terminal81. The operations in steps S36 and S37 for terminating the service arethe same as those in the steps S6 and S7 in FIG. 4.

In this way, in this embodiment the present position is obtained by theVICS arithmetic circuit 152, while the reproducing unit 39 in FIG. 18becomes unnecessary because the map data itself is transmitted from theserver 86, thus achieving the decrease in size accordingly.

FIG. 16 shows a different arrangement of the portable terminal 81. Thisembodiment includes a reproducing unit 161 so that the map data recordedin a CD-ROM or the like is read out and displayed on the display section95. Accordingly, in this embodiment, there is no need to transfer themap data itself from the server 86. However, in this case, thereproducing unit 161 increases the size of the portable terminal 81,whereas the GPS arithmetic circuit 143 in FIG. 12 and the VICSarithmetic circuit 152 in FIG. 14 are omitted. Further, as well as theFIG. 2 embodiment the CPU 91 detects the present position by receivingthe ID number of the base station 85 through the communication circuit98 and transmits the ID number as the present position to the server 86.Accordingly, in this embodiment it is possible to suppress the increasein size of the portable terminal by a quantity corresponding to thereceiving circuit 36 and the arithmetic circuit 37 of the portableterminal 11 in FIG. 18.

Although in the above description the present invention is applied tothe portable terminal, this invention is also applicable to a terminalunit which is mounted on a motor vehicle and moved together therewith.According to this invention, it is possible not only to decrease thesize of the terminal unit, but also to make the terminal unit easy tocarry, and even to lower the cost. Moreover, since the map informationis received with a scale allowing the simultaneous display of thepresent position and the destination, it is possible to quickly andaccurately find the direction of the destination and hence to quicklyreach the destination.

It should be understood that the foregoing relates to only preferredembodiments of the present invention, and that it is intended to coverall changes and modifications of the embodiments of the invention hereinused for the purposes of the disclosure, which do not constitutedepartures from the spirit and scope of the invention.

1. An information providing method comprising the steps of: receivingfrom a terminal unit a signal to be used to determine a present positionof said terminal unit other than by said terminal unit at a positionapart from said terminal unit, said signal including azimuth informationand said signal being demodulated from a multiplexed signal previouslyreceived by said terminal unit; determining the present position of saidterminal unit on the basis of said received signal from said terminalunit without position determination processing having been performed onthe demodulated signal at said terminal unit to determine the presentposition of said terminal unit; and transmitting the determined presentposition to said terminal unit.